In transformer, a Sweep Frequency Response Analysis (SFRA) test will help detect ____

• A. Age of the insulation
• B. Moisture in the windings
• C. Aging by-products
• D. Movement / damage to internal components

Answer: (D)

Frequency response analysis is the technique whereby a sinusoidal test signal is used to measure points on the frequency response of a transfer function or impedance function.
Sweep Frequency Response Analysis (SFRA) testing provides insight into the mechanical and electrical integrity of transformers.

Main Purpose of SFRA Test:
Transformer Core displacement
Winding displacement for both rotor and transformer
Broken or loosen clamp connections
Inter turn short circuit
Internal short circuit
Winding to Core Earth fault
Winding Open circuit condition